Electric switch



Oct; 18, 1938. A, w, KR|EGER 2,133,545

ELECTRIC SWITCH Filed June 11, 1936 3 Sheets-Sheet l I N5 ULATI ON Oct. 18, 1938. A. w. KRIEGER ELECTRIC SWITCH Filed June 11, 1936 3 Sheets-Sheet 2 Oct. 18, 1938. A. w. KRIEGER 2,133,545

ELECTRIC SWITCH Filed June 11, 1936 3 Sheets-Sheet 3 Patented Oct. 18, 1938 PATENT OFFICE ELECTRIC SWITCH Alvin W. .Kl'ieger, Cutler-Hammer, poration of Delaware Milwaukee, Wis., assignor to Inc., Milwaukee, Wis., a cor- Application June 11, 1936, Serial No. 84,653 19 Claims. (01. Z-163) This invention relates to improvements in electric switches, and more particularly to improvements in slow-make, slow-break switches for control of alternating current circuits.

A primary object of the invention is to provide a switch of the aforementioned character of relatively small size but of relatively large current controlling capacity.

Another object is to provide means for minimizing arcing between the stationary and movable contacts of such switches, whereby the life and current controlling capacity thereof are in creased.

Another object is to provide switches of the aforementioned character having improved forms of movable and stationary contacts, and improved forms of wiring terminal elements for the latter.

Another object is to provide novel forms of supporting and actuating means for the stationary and movable switch parts.

Another object is' to provide a toggle-lever actuated switch of the character aforementioned.

Another object is to improve and simplify construction and assembly of the switch parts and the operating characteristics thereof.

Another object is to provide a novel form of slow-make, slow-break .switch of the multiplepole type.

Another object is to provide a novel form of insulating plunger for effecting operation of the movable contact elements of the switch.

Other objects and advantages of the invention will hereinafter appear.

The accompanying drawings illustrate certain embodiments of the invention which will now be described, it being understood that the embodiments illustrated are susceptible of modification in respectof certain details of construction thereof without departing from the scope of the appended claims.

In the drawings, Figure 1 is a top plan view (twice normal scale) of the base and the stationary contact and terminal members of a doublepole, slow-make, slow-break switch for control of alternating current circuits.

Fig. 2 is a vertical sectional view, on the line 2-2 of Fig. 1, but with all of the switch parts in assembled position.

Fig. 3 is a vertical sectional view, on the line 3-3 of Fig. 1, showing the switch parts assembled, as in Fig. 2.

Fig. 4 is a perspective view of one of the onepiece combined contact and terminal members employed in the switch of Figs. 1 to 3.

Fig. 5 is a perspective view, in separated re-' actuating lever being broken away.

therewith being shown in separated relation.

of the insulating plunger and the conplate to be associated lation, tactors and insulating therewith.

Fig. 6 is an enlarged vertical sectional view (four times normal scale), on the line 6-6 of 5 Fig. 1, with all of the switch parts assembled, the upper end portion of the switch being broken away.

Fig. '7 is a view similar to Fig. 1, but showing a modification wherein only two combined stationary contact and terminal members and a single contactor are employed, to provide a slow-make, slow-break switch of the single-pole type. v

Fig. 8 is a perspective view of the single contactor employed in the switch of Fig. 7.

Fig. 9 is a top plan view, actual size, of another form of double-pole switch embodying my invention, said switch being of substantially greater current controlling capacity than that shown in Figs. 1 to 8. Fig. 10. is a vertical sectional view, on the line Ifl-Jfl of Fig. 9.

Fig- 11 is a top plan view of the lower section of the insulating casing of the switch, showing the stationary and movable contact elements in position. I 1 Fig. 12 is a bottom plan view of the molded insulating casing of the switch.

Fig. 13 is an enlarged vertical sectional view,

on the line |3l3 of Fig. 10, a portion of the Fig. 14 is a vertical sectional view, on the broken line l4-I4 of Fig. 13.

Fig. 15 is a detail perspective view of one-set of stationary contacts and the contactor associated therewith. Fig. 16 is a. perspective view of the insulating plunger employed with the switch of Figs."-9 to 15, the cylindrical metal member associated actual size,

Fig. 17 is a top plan view of the lower insulating casing section of a three-pole switch which is quite similar in construction to that shown in Figs. 9 to 16, the pairs of stationary contacts and the contactors being shown in assembled position. A Fig. 18 is a perspective view of the insulating plunger employed with a switch of the character illustrated in Fig. 1'7, and -l 1,1

19 is a vertical sectional view, similarc-to Fig. 13, but showing a. three-pole switchaof'lthe character illustrated in Fi 1'7. I i Referring first to Figs. 1 to 6 of the drawings, the numeral 20 designates a base molded from a suitable insulating material. such as the phenoli formaldehyde condensation product known as Bakelite. Base 20 is preferably of substantially rectangular contour, and the same is provided with an upwardly opening main recess 2| of substantially rectangular contour.- Base 20 is provided at the four corners thereof with relatively small substantially rectangular recesses 22, 23, 24 and 25, the bottom walls of said last mentioned recesses being located in a common plane offset upwardly from the bottom wall of the main recess 2|, as shown in Fig. 3. Said relatively small recesses are provided with spaced wall portions 22, 22 23 23 24*, 24 and 25525", the spacing of said wall portions affording restricted communication between said recesses and'the main recess 2|. Also, as best illustrated at 24 25 in Fig. 3, said spaced wall portions are preferably interrupted at a point substantially below the upper surface of base 20.-

The opposite end walls of base 20 are respectively provided with grooves 22, 23, 24, 25 which are of sufficient depth and of proper shape to accommodate in a substantially flush relation 1 to the upper surface of base 20 the insulated portions of circuit wires (not shown) when a switch of the concealed wiring type is desired. Said grooves are provided at the sides thereof adjacent to the respective longitudinal side walls of base 20 with auxiliary vertically walled grooves 22,

23 24 and 25 (as best illustrated at the righthand end of the base 20 in Fig. 7), which auxiliary grooves are respectively adapted to receive the correspondinglyshaped terminal portions 26, 21, 28 and 29 of the one-piece combined contact and wiring terminal members employed in the switch of Figs. 1 to 6. As shown in Fig. 3, said terminal portions are adapted to seat within said auxiliary grooves in a relation substantially flush with the upper surface of base 20.

One of said combined contact and terminal members 29 is shown in detail in Fig. 4, the terminal portion 29 thereof comprising an extension of substantially annular contour, whereby a circuit wiremay be looped thereinto, and attached thereto by twisting and/or soldering in the usual manner. The portion 29 is bent inwardly at substantially a right angle to the plane of the terminal portion 29, and portion 29 is insertable into recess 25 (Fig. l) whereby the lower portion thereof. is positioned behind 'the aforementioned wall portions 25, 25*, as best illustrated in Fig. 3. Extending downwardly and then outwardly from the portion 29 is a reduced portion or neck 29, the outwardly extending part of which carries the enlarged head or tip 29 which forms one of the stationary contacts of the switch.

As illustrated in Fig. 3, the arrangement is such that tip 29 is rigidly positioned within main recess 2| in upwardly offset relation to the bottom wall thereof, and said tip 29 and portion 29 are interlocked with the respective opposite sides of wall portions 25, 25 to prevent movement of the combined contact and terminal member laterally or longitudinally of base 20. Members 29 and 21 are of identical (left-hand) form, whereas members 26 and 28, which are made from blanks identical with those employed for members 29 and 21, are bent to right-hand form- The bottom wall of main recess 2| is preferably provided centrally thereof with a boss or projection 2| which acts as a positioning abutment for the lower end of a coiled compression spring 36. A similar result might, of course, be obtained by providing in the bottom wall of recess 2| an auxiliary'recess to accommodate the lower end of said spring. Located within main recess 2| is a molded insulating plunger 3| of the form best illustrated in Fig. 5. Said plunger comprises a substantially cylindrical portion 3| having a flat cruciform flange ill formed integrally with the lower end thereof, the respective ends of said flange being slidably engageable with the side walls of recess 2| to assist in guiding the plunger 3|. The form of flange 3| likewise provides clearance between the same and the aforementioned contact tips (see Fig. 1). Plunger 3| is provided in its lower end with a cylindrical re-. cess 3| (Figs. 2 and- 6) to accommodate the upper end of spring 30, said recess being sufllciently deep to accommodate substantially the entire body of said spring when the latter is compressed by downward movement of the plunger.

The upper end of plunger 3| is provided with a reduced portion 3| which is preferably of rectangular form in transverse cross section, said portion 3| having a relatively long upwardly angled cam surface 3| and a relatively short horizontal surface 3| Superimposed upon the upper surface of base 20 is a flat punched insulating plate 32 which is adapted to be secured thereto in the manner hereinafter described to retain the combined contact and terminal members in position, as best illustrated in Fig. 3. Plate 32 is provided with a rectangular opening 32* (Figs. 2 and 6) to accommodate with a sliding flt the reduced upper end portion 3| of the plunger, to further assist in guiding the latter. Spring is adapted to bias the plunger upwardly, wherefore the horizontal shoulder formed between cylindrical portion 3| and reduced portion 3| is adapted to bear against the lower surface of plate 32.

The form of the bridging contactors 33 and 34 is best illustrated in Fig. 5, it being understood that said contactors are normally supported upon the hat upper surface of flange 3| of the plunger in positions respectively overlying the longitudinally spaced pairs of contact tips 26 28 and 21, 26 Contactors 33 and 34 are preferably provided intermedite the length thereof with upwardly extruded hemispherical bosses 33', 34,

respectively. Slidable onto the cylindrical portion 3| of the cylinder and adapted to overlie said contactors 33 and 34 is a flat punched insulating plate 35. Interposed between the upper surface of said plate 35 and the lower surface of plate 32 and surrounding the cylindrical portion 3| of the plunger is a coiled compression spring 36, which normally acts to bias contactors 33 and 34 into bridging engagement with the pairs of contact tips. However, the spring 30 is of greater strength than spring 36, wherefore the latter becomes effective for closing the controlled circuit or circuits only upon a predetermined degree of downward movement of the plunger.

Superimposed upon the insulating plate 32 is a punched and stamped sheet metal top plate 31, base 20 and plates 32 and 31 having alined openings formed therein to receive the shanks of headed rivets 38 and 38, the ends of which are upset over top plate 31 to rigidly and permanently secure the aforedescribed parts in assembled relation. Top plate 31 is provided with an upwardly oflset inwardly extending annular flange 21- which receives the reduced lower end 40! of an externally threaded hollow metal bushing 4|, said reduced end 40 being upset over the lower sura. 43 carried by lever 4| acts cooperates with the bosses 33,

face of flange 31" to rigidly secure said parts in assembled relation. Bushing 40 is preferably provided with a vertical groove 40 which receives a lug 3! on flange 31 to insure against rotary displacement of the bushing, said groove 40 also serving in the usual manner to properly position an on and off indicating plate for the switch, if desired.

Bushing 48 is provided with alined pivot openings and a metal lever 4| positioned therewithin is provided with a relatively smaller opening, the latter being adapted to accommodate with a. drive or press fit the slightly enlarged intermediate portion of a pivot pin 42. The upper end of lever 4| is preferably provided with a knob or enlargement 4| to facilitate manipulation thereof. The lower end of lever 4| is provided with a substantially cylindrical recess (not shown) to accommodate the upper end of an insulating pin 43 having a rounded or hemispherical lower end which is engaged at all times with one or the other of the cam surfaces 31, 3| at the upper end of plunger 3|. Pin 43 preferably comprises a length of a rod of impregnated fiber or other wear-resisting material, or the lever may have a projection formed integrally therewith to perform the function of pin 43.

With the lever 4| in the right-hand position thereof shown in Figs. 2 and 3 the spring 30' acts to lift plunger 3| to its upper extreme position, whereby contactors 33 and 34 are disengaged from the respective pairs of contact tips 28, 28 and 21, 26 as best illustrated in Fig. 3. Upon manual operation of lever 4| toward the left pin upon the cam surface 3| to force plunger 3| downwardly against the action of spring 30. Under these conditions the spring 36 is free to bias the contactors downwardly into bridging engagement with the aforementioned pairs of contact tips whereby the controlled circuit is completed. Insulating plate 35 34'- formed upon the contactors to insure self-adjustment of the latter with respect to the pairs of contact tips engaged thereby.

Also it is to be understood that upon movement of lever 4| to its extreme left-hand position the lower end of pin 43 will ride onto the horizontal cam surface 3| whereby all of the switch parts will remain in their circuit closing positions. Thereafter the lever 4| may be moved toward the right to effect disengagement of pin 43 from horizontal cam surface 3| and engagement thereof with cam surface 3| whereby the plunger is permitted to gradually move upwardly under the action of spring 38 to effect disengagement of the contactors from the pairs of contact tips. Due to the cam action aforedescribed such disengaging movement of the contactors is efiected at a relatively slow rate, and this .is of importance since the described switch is intended and adapted for control of alternating current circuits. Thus the potential of the controlled current will reach zero value during the disengaging movement of the contactors, whereby actual interruption of the controlled circuit with a minimum of arcing is insured. In practice both the contacts and the contactors employed in the switch of Figs. 1 to 6 may be formed of a metal such as brass. A switch of the size illustrated in these figures has a rated capacity of 15 amperes at volts alternating current. The arrangement of parts, moreover, insures an extremely long life for the switch.

Referring particularly to Figs. 2 and 3, it will corresponding parts be understood 'that one or more clamping nuts (not shown) Will be provided to afford the usual one-hole mounting for the switch.

The single-pole switch illustrated in Figs. 7 and 8 difiers from that aforedescribed in respect of the omission of two of the combined contact and terminal members 26 and 29, and the use of a single bridging contactor 44, the form of which is best illustrated in Fig. 8. the switch of Figs. '1 and 8 are identical with the aforedescribed. Thus in one position of the actuating lever 4| aforedescribed the plunger 3| will be depressed to permit spring 36 to effect engagement of contactor 44 with the laterally alined pair of contact tips 21 and 26. whereas in the other position of said lever the spring 38 will lift plunger 3| with consequent disengagement of contactor 44 from said pair of contact tips. The single-pole switch of Figs. '7 and 8 will.have a rating or capacity equal to that of the double-pole switch aforedescribed.

In Figs. 9 to 16, inclusive, I have shown a modified form of double-pole, slow-make, slow-break switch for control of alternating current circuits, said switch being of relatively larger size than the switches aforedescribed, as indicated by the actual size views of Figs. 9 and 10 (for instance). In Figs. 9 to 16 the numeral 45 designates a molded insulating base having an approximately rectangular recess 46 formed therein and ing to the upper surface thereof. Base 45 is provided with four flat punched sheet metal contact members 41 of identical form, said contact members being respectively seated upon ledges The other parts of openlocated in a common plane oifset downwardly :5,

from the upper surface of said base, as best illustrated in Fig. 14. The tips of said contact members respectively overlie vertical grooves or extensions of the recess 46 to accommodate a pair of bridging contactors 48 of identical form.

Those portions of recess 46 and the pairs of vertical grooves which accommodate the bridging contactors are of less depth than the main portion of said recess, as indicated by the bottom wall portions 46*, 46 in Fig. |3. Each of said bottom wall portions is provided with a centrally locatedcylindrical recess 46, 46* toaccommodate the lower ends of a pair of coiled compression springs .49 and 50. The upper ends of said springs are respectively adapted to receive the cylindrical bosses or extrusions 48 formed upon the lower surface of each contactor. Accordingly the contactors 48 are normally biased upwardly into bridging engagement with the respective longi dinally spaced pairs of contact tips.

' In practice the main po' ions of contact members 41 and contactors 48 are formed of brass or a similar inexpensive metal of good current upwardly from the bottom surface of base 45, and

a corresponding number of internally threaded hollow metal eyelets 5| are inserted upwardly of a layer or inlay of sublet 52 and screw 52.

therethrough and upset over said contact members, as shown at 5i in Figs. 11 and 14. Said eyelets are provided with heads of square or other polygonal form, as shown at 5|, and said heads are seated in countersinks or recesses of corresponding form in a relation substantially flush with the lower surface of said base. The lower surface of base 45 is preferably provided with integral insulating barriers 45 45 45 and 45 which separate the aforementioned eyelet heads from each other. A fifth eyelet 52 is pref erably attached to the lower surface of base 45 between the barriers 45, 45', whereby the switch is adapted to accommodate the neutral wire of a three-wire source of current supply. All of the aforementioned eyelets are provided with binding screws of well known form, the screws 5| preferably having long shanks, as illustrated in Fig. 14, and the screw 51! preferably having a relatively short shank, as illustrated in Fig. 13.

A molded insulating plunger 53 is provided, said plunger having a main body portion 53 of substantially rectangular form in transverse cross section. Plunger 53 is provided with a pair of laterally extending arms 53 and 53 against the under surfaces of which the contactors 48 are adapted to bear, under the bias of springs 49 and 50, as aforedescribed. A punched plate of insulating material 54 is positioned upon the upper surface of base 45 to substantially close the recess in the latter, plunger 53 having an .upwardly extending portion 53 of substantially rectangular cross section, and plate 54 having an opening 54 formed therein to accommodate said extension and to assist in guiding the plunger. Plunger 53 is preferably provided with vertical ribs or projections 53, 53 which are accommodated within vertical grooves 46, 46 formed in the side walls of recess 46, as best illustrated in Figs. 10 and 13.

The lower end of plunger 53 is preferably prcvided with a recess 53 to insure clearance between said plunger and the aforementioned eye- The upward extension 53 of the plunger is provided with an upwardly and laterally opening recess 53 (Figs. 10, 13 and 16), the curved bottom wall 53 of which is adapted to provide a bearing for the rotatable metal disk or cylinder 55, the upper end of which is preferably substantially flush with the upper end of the plunger extension SF. The springs 49 and 50 normally bias the contactors 48 upwardly into,

engagement with the respective pairs of contacts, as best illustrated in Fig. 14, the plunger 53 being supported in its upper extreme position by said contactors.

The means for effecting disengagement of contactors 48 from the pairs of contacts comprises a lever 56 pivotally supported by a pin 51. The lower edge of said lever is provided with cam surfaces 56, 55', the arrangement being such that in the position of the lever illustrated in Figs. 10 and 14 the cam surface 56 cooperates with disk 55 to permit upward movement of contactors 48 into bridging engagement with the contacts. As best. illustrated in Fig. 13, the cam surface 56 is slightly spaced from disk 55 in the upper extreme position of the plunger, to insure proper engagement of the contactors with the contacts when the lever 56 is moved to on position. Upon movement of lever 55 to its left-hand extreme position. the cam surface 56 is engaged with disk 55 to depress plunger 53,.with consequent disengagement of the contactors 48 from the contacts. The disengaging movement of contactors 48 is effected at a relatively slow rate whereby the potential of the controlled alternating current circuit is adapted to attain zero value during the circuit interrupting operation to mini mize arcing, as aforedescribed. The inlaid coin silver tips of the contactors 48 and contacts 41 assist in increasing the current controlling capacity of the switch as well as the life thereof. The switch of Figs. 9 to 16 has a rated capacity of 30 amperes at volts alternating current.

The pivot pin 51 is adapted to seat within notches 58 553 formed in the upper surface of a molded insulating cover member 58, a punched and stamped sheet metal supporting plate 59 being adapted to overlie said cover member, and a pair of screws 60 and 6| extending upwardly through base 45, plate 54, cover member 58 and top plate 59 to secure said parts in assembled re-. lation. Cover member 58 is recessed, as shown at 58 in Fig. 13, to provide clearance for the extension 53 of the plunger and to assist in guiding the latter; the upper wall of said recess having an opening 58 to provide clearance for lever 56.

Lever 56 is provided at a point below the pivot pin 51 with a pin 62 which is provided intermediate its ends with an integral annular shoulder 62* to prevent endwise displacement of the pin in one direction, and said pin is provided' with an annularly upset portion 62 to rigidly attach the same to said leverand to prevent endwise displacement of the pin in the opposite direction. Cover member 58 is provided on opposite sides of lever 56'with a pair of passages 58 and 58 (Fig. 13) having restricted upper ends to limit the upward displacement of a pair of metal balls 63 and 64, said balls being biased upwardly by the respective coiled compression springs 65 and 66, the lower ends of which are seated against the upper surface of plate 54.

The spring pressed balls 63 and 64 cooperatively engage the respective ends of pin 62 to insure positive positioning of lever 56 in one or the other of its extreme positions, and to afford the desired indication to the touch that the switch parts have been moved to circuit making or circuit breaking position. Lever 56 may be provided at its upper end with a knob 56 to facilitate manipulation thereof, or the same may be otherwise formed in a manner (not shown) to cooperate with any suitable form of actuating element. Supporting plate 59 may be provided with legends, as shown'in Fig. 9, to indicate. the on and oil? positions of the switch. Plate 59 is preferably provided with upwardly offset ends 59*, 59 having openings 59, 59 to accommodate suitable means (not shown) to provide for attachment of said plate to a suitable support, the base 45, plate 54 and cover member 58 having grooves formed in the opposite ends thereof and alined with top plate openings 59 and 59 (as shown in Fig. 10) to accommodate such fastening members.

The structure of the three-pole switch shown in Figs. 17 to 19 is quite similar to that of the switch of Figs. 9 to 16, except that it is of slightly greater width to accommodate the additional contactor and the pair of contacts for cooperation therewith. Thus I provide a molded insulating base 61 having a recess 51' opening to the upper surface thereof, three pairs of opposed vertical grooves being provided which communicate with said recess and openupwardly to ledges offset downwardly from the upper surface of the base. Six punched sheet metal contacts 68 of like form are seated upon the respective ledges with the tips thereof overlying the aforementioned vertical grooves. Said tips are of reduced width to afford proper spacing between the same and the side walls of the vertical grooves, as shown in Fig. 17. This arrangement eliminates the possibility or danger of the formation of a film of metal particles upon the recess walls adjacent to the point of engagement and disengagement of the switch contacts.

Underlying each pair of contact tips, and of a width equal thereto, are three punched sheet metal contactors 69 of like form. Each of said contactors is provided on the lower surface thereof with an extruded boss 69* to form an abutment for the upper end of a 10, the lower ends of the springs 10 being seated in auxiliary recesses 61, 61 and 61 formed in base 61 (Fig. 19). Each of the contactors 69 is provided with a laterally projecting lug 69 to cooperate with one of the vertical grooves 1|, N 1 or 1 I formed in the downward extensions 1 l and 1 I of plunger 1| to prevent endwise displacement of said contactors. The contactingsurfaces of said contactors and contacts are preferably provided with inlays of coin silver, as described in respect of the switch of Figs. 9 to 16.

The form of plunger II is best illustrated in Fig. 18; and as shown in Fig. 19 base 61 is provided with auxiliary recesses 61 and 61 to accommodate the extensions 1 l' and 1 I to assist in guiding the plunger. The springs 10 act in the manner aforedescribed to bias the contactors 69 upwardly into engagement with the respective pairs of contact tips, the plunger being supported by said contactors in the mannerillustrated in Fig. 19.

Plunger 1| is provided with an upward extension II of substantially rectangular contour, said extension having an upwardly and laterally opening recess 1 which is adapted to receive the rotatable disk or cylinder 12. The lever 56 may be identical with the corresponding part aforedescribed, the cam surfaces formed upon the lower edge thereof being adapted in one position of the lever to permit upward movement of the contactors under the bias of springs 1|! and in the other position thereof to eflfectdownward displacement of plunger 1| against the bias of said springs with consequent disengagement of contactors 69 from the pairs of contacts.

Lever 56 is pivotally supported by a pin 1% which is seated within notches Il and 14 formed in the upper surface of the molded insulating cover member 14. The switch is provided with a metal top plate 15, which is preferably of greater width than the top plate 59 aforedescribed, and the same is provided with a pair of tapped openings (not shown) to receive the shanks of securing screws extending upwardly through passages 61, 61 in base 61 (see Fig. 1'7). Cover member 14 is provided with a recess 14 to accommodate the extension H of the plunger, the upper wall of said recess being provided with an opening 14 to accommodate the lower end of lever 56. A pin 16 is attached to lever 56 in the manner aforedescribed, and balls 11 and 18 are pressed upwardly against the respective ends of said pin, as by means of springs 19 and 80 the lower ends of which are seated against the upper surface of the punched insulating plate 8|. springs 19, 80 and balls 11, 18 are located within passages 1451-4 formed in cover member 14, the ends of pin 15 serving in each position of lever 56 to prevent excessive upward displacement of balls 11, 18,

As shown in Fig. 30f the drawings, and as coiled compression spring -ment thereof in one The . plunger,

be understood from the various other figures, only a relatively small degree of movement of the contactors is required to effect interruption of the controlled circuit or circuits. The advantages of the structifral features and operative characteristics of my improved switch mechanisms will be apparent to those skilled in the art. The switch parts are of simple form and the assembly thereof'is facilitated, The arrangement is also such that partial or complete dis-assembly is facilitated to provide for repair orreplacement of the switch parts. The switches illustrated are of relatively small dimensions and the means illustrated, or any other suitable means, may be employed for mounting the same in the handle of a portable tool or the like.

What I claim as new and Letters Patent is:

l. A slow-make, slow-break switch comprising an insulating base having a recessformed therein and opening to one surface thereof, a plurality of pairs of stationary contacts located within said recess, the contacts of the respective pairs being spaced from each other longitudinally of said base and having wiring terminal elements located exteriorly of the latter, an insulating desire to secure by plunger slidable'withln said recess and guided by the side walls of the latter, a plurality of bridging contactors associated with said plunger, said contactors and said plunger being movable relatively to each other, spring means for jointly biasing said plunger and said contactors toward the upper extreme positions thereof respectively, an insulating member overlying the upper surface of said base and engageable by said plunger to limit the upward movement of the latter, a cam surface associated with said plunger, a member movably supported with respect to said base and having a portion engageable with said cam surface for releasable restraint by the latter in either positions of the former, said last adapted upon moveof the extreme mentioned member being downward movement of said plunger, and associated means ,for simultaneously efiecting extreme downward movement of said contactors, said contactors being engaged with and disengaged from said pairs of contacts in the respective extremepositions of the former. a

2. A slow-make, slow-break switch of relatively small size with reference to its capacity, comprising a molded insulating base having a recess formed therein and opening to one surface thereof, a plurality of pairs of ledges offset downwardly from the upper surface of said base and communicating with said recess, a plurality of contacts respectively seated upon said ledges and having the tips thereof located within said recess, wiring terminal elements electrically connected with the respective contacts and having portions thereof accessible for wiring at the outer surface direction to eflect extreme of said base, a member of insulating material having a lower end portion engageable with said said actuating member cooperating with said plunger to provide for the aforementioned upper extreme positioning of said plunger and said contactors in one extreme position of said actuating member, and said actuating member being movable to another extreme position thereof to provide for joint movement of said plunger and said contactors in the reverse direction and retention thereof in the lower extreme positions thereof respectively.

3. A slow-make, slow-break switch of small size but of relatively large alternating current controlling capacity, comprising a molded in-- sulating base having a recess formed therein and opening to the upper surface thereof, a plurality of pairs of stationary contacts located within said recess, the contacts of the respective pairs being spaced longitudinally of said base and having wiring terminal elements located exteriorly of the latter, an insulating plunger slidable with: in said recess and guided by the side walls of the latter, a coiled compression spring interposed between the bottom wall of said recess and said plunger to bias the latter upwardly to a given extreme position, a plurality of bridging contactors loosely carried by said plunger and adapted to overlie the longitudinally spaced contacts of said pairs, at flat punched plate of insulating material loosely carried by said plunger and adapted to overlie said contactors, a coiled compression spring carried by said plunger above said plate, a fiat punched plate of insulating material overlying the upper surface of said base and engaged with said plunger and said second mentioned spring, are compressed to predetermined degrees, said last mentioned plate having an opening and said plunger having a portion thereof extending upwardly through said opening, means pivotally supported with respect to said base and engageable with said extending portion of said plunger, said means being adapted in one position thereof to permit disengagement of said contactors from said contacts by said first mentioned spring, and said means being movable to and releasably restrained in another position thereof to effect a further degree of compression of said first mentioned spring, whereby said second mentioned spring is rendered effective to engage said contactors with the respective pairs of contacts,

4. A slow-make, slow break alternating current controlling switch of relatively small size with reference to its capacity, comprising a molded insulating base having a recess formed therein and opening to the upper surface thereof, a plurality of pairs of ledges offset downwardly from the upper surface of said base, a plurality of fiat punched sheet metal contacts respectively seated fiatwise upon said ledges and having the tips thereof located within said recess, wiring terminal members having portions thereof exposed upon the lower surface of said base and having other portions thereof upset over the respective contacts to secure the latter in position, a fiat punched plate of insulating material overlying the upper surface of said said plate having a substantiallycentrally located opening formed therein, an insulating plunger located within said recess and guided by the side walls thereof, said plunger having a reduced end portion extending upwardly through said plate opening and a shoulder engageable with said plate to limit upward movement of the plunger, a plurality of bridging contactors loosely associated with said plunger and movable relatively to the latter, spring means carried by said base for Jointly effecting movement of said plunger and whereby both of said springsv base and secured thereto,

said contactors in one direction to given extreme positions thereof respectively, an actuating member supported above said base and having a lower end portion in continuous engagement with the reduced end of said plunger, said reduced end and said member having cooperatively formed surfaces to provide for the aforementioned positioning of said plunger and said contactors in one position of said member, and said member being movable to and releasably restrained in another position thereof to effect disengagement of said contactors from said contacts by said plunger.

5. In an electric switch, in combination, a molded insulating base having a main recess formed therein, said base also having a plurality of relatively small recesses formed in each end thereof, all of said recesses opening to the upper surface of said base and said relatively small recesses communicating with said main recess at and below said upper surface, a corresponding number of one-piece combined contact and wiring terminal members having portions thereof seated within said relatively small recesses and having contact portions thereof located within said main recess in upwardly spaced relation to the bottom wall of the latter, said members having wiring terminal portions extending from said base in a relation substantially flush with said upper surface, an insulating plunger located within said main recess, said plunger having a main portion and a cruciform flange at its lower end to provide for guiding thereof by the side walls of said main recess and to provide clearance between said plunger and said contact portions, said plunger having a recess in the lower end thereof, a coiled compression spring interposed between the inner wall of said last mentioned recess and the bottom wall of said main recess to bias said plunger to its upper extreme position, a pair of punched sheet metal contactors loosely seated upon the upper surface of said flange, each of said contactors being guided by certain of the side walls of said main recess and by said plunger, a flat punched insulating plate carried by said plunger and superimposed upon said contactors, a coiled compression spring surrounding the main portion of said plunger and seated upon the upper-surface of said plate, said plunger having a reduced upper end providing a shoulder, a flat punched plate of insulating material secured to the upper surface of said base and adapted to overlie all of the aforementioned parts to retain the same in assembled position,

- plate being engaged with said shoulder to initially depress said plunger and said first and second mentioned springs to predetermined degrees, said reduced upper end of the plunger having a cam surface formed thereon, and a lever pivotally sup ported with respect to said base, said lever having an abutment at the lower end thereof cooperable with said cam surface to provide for further depressing and releasably restraining said plunger against the action of said first mentioned spring whereby said contactors are engaged with said contacts under the action 'of said second mentioned spring.

6. In an electric switch of the character described, in combination; a molded insulating base having a recess formed therein and opening to the upper surface thereof, aplurality of pairs of contacts having the tips thereof located within said recess and having wiring terminal portions having exposed upon the outer surface of said base, a molded insulating plungerslidable within said recess and guided in part by the side walls of the' latter, said plunger having arms or flanges formed thereon and located in a common plane, a plurality of punched sheet metal contactors loosely associated with the arms of said plunger for movement by-the latter to one extreme position, spring means associated with said contactors to bias the latter to their opposite extreme position, a flat punched insulating plate superimposed upon the upper surface of said base, said plate having an opening and said plunger having a reduced upper end slidable in said opening to assist in guiding said plunger, said plunger having a shoulder engageable with said plate to limit upward movement of the former, a lever pivotally supported above said base, the lower end portion of said lever and the reduced end of said plunger being cooperatively formed to effect and permit movement of said plunger and said contactors toopposite extreme positions thereof respectively upon movement of said lever to its opposite extreme positions selectively, and said plunger acting to releasably restrain said lever in each of the extreme positions of the latter.

'7. A relatively small slow-make, slow-break switch having a relatively large alternating current controlling capacity, comprising a molded insulating base having a recess formed therein and opening to the upper surface thereof, said base having a plurality of pairs of ledges formed therein and oifset downwardly from said upper surface, a corresponding number of sheet metal contacts seated upon the respective ledges with the tips thereof projecting into said recess, a

bridging contactor underlying each longitudinally alined pair. of contact tips, a spring interposed between each contactor and the base to normally bias said contactors into bridging engagement with the respective pairs of contact tips, a. molded insulating plunger freely insertable into said recess and slidably engaging the walls thereof, said plunger having portions thereof seated upon the respective bridging contactors intermediate the ends of the latter for support thereby, a flat plate of insulating material overlying the upper surface of said base, said plate having an opening and said plunger having a reduced portion extending upwardly through said opening, said reduced portion having an upwardly opening pocket formed therein, a metal member rotatably seated within said pocket, and a lever pivotally supported above said base, said lever a cam surface formed thereon at the lower end thereof and adapted for continuous engagement with said metal member, said cam surface being adapted upon movement of said lever in one direction to efiect downward movement of said plungerwhereby said contactors are disengaged from said pairs of contact tips against the action of said springs, and said cam surface acting to releasably restrain said lever in each of its extreme positions.

8. A switch comprising an insulating base having a recess formed therein and opening to the upper surface thereof, said recess including a plurality ofzpairs of vertical pockets, the pockets of said pairs being spaced longitudinally of said base, said base having a. plurality of pairs of ledges formed therein and located in a common plane, a corresponding number of flat sheet metal contacts of like form seated upon the respective ledges and having the tips thereof overlying the respective vertical pockets, a plurality of sheet metal contactors the opposite ends of which respectively underlie said pairs of contact tips, said contactors being individually spring biased upwardly into engagement with saidpairs of contact tips, means for rigidly and permanently securing said contacts to said base, said means comprising a. corresponding number of internally threaded hollow metal members extending upwardly from the lower surface of said base and upset over said contacts, wiring terminal screws having threaded engagement with said hollow metal members and accessible from the lower surface of said base, an insulating plunger freely insertable into said recess and slidably engaging the walls thereof, said plunger having portions thereof seated upon the respective bridging contactors intermediate the ends of the latter for support thereby, an insulating member overlying the upper surface of said base, a punched sheet metal lever pivotally supported by said insulating member, said lever having a cam surface formed thereon and adapted for cooperation with said plunger, said lever being adapted upon movement thereof in one, direction to efiect downward movement of said plunger and said contactors, said lever being adapted upon reverse movement thereof to permit upward movement of said plunger and said contactors under the bias of said springs and said plunger acting upon said lever to releasably restrain the latter in either of its extreme positions.

9. A switch comprising a molded insulating base having a recess formed therein and opening to the upper surface thereof, said recess including a plurality of pairs of vertical pockets, the pockets of said pairs being spaced longitudinally of said base, said base having a plurality of pairs of ledges formed therein and located in a-common plane, a corresponding number of flat punched sheet metal contacts seated upon the respective ledges and having the tips thereof overlying the respective vertical pockets, a plurality of punched sheet metal contactors the opposite ends of which respectively underlie said pairs of contact tips, said contactors being spring biased upwardly into engagement with said pairs of contact tips, means for rigidly and permanently securing said contacts to said base, said means comprising a corresponding number of internally threaded hollow metal members having wiring terminal screws accessible from the lower surface of said base, a plunger freely insertable into d recess and slidably engaging the walls thereoffsaid plunger having portions thereof seated upon the respective bridging contactors for support thereby, an insulating member overlying the upper surface of said base, a punched sheet metal lever pivotally supported by said insulating member, said lever having a cam surface formed thereon and adapted for cooperative engagement with said plunger, said lever being adapted upon movement thereof in one direction to effect downward movement of said plunger and said contactors, said lever being adapted upcn reverse movement thereof to permit upward movement of said plunger and said contactors under the bias of said springs, said insulating member having a plurality of spring-pressed parts associated therewith to pro-,

vide yieldable obstructions, and said lever having parts associated therewith for cooperation with said spring-pressed parts to yieldably resist movement of said lever in either direction and to insure movement of the latter to one or the olded insulating other of its extreme positions upon release thereof.

10. In a slow-break switch for control of alternating current circuits, in combination, an insulating base having a recess therein opening to the upper surface thereof, a plurality of pairs of sheet metal contact members secured to said base adjacent to the upper surface thereof, the tips of said contact members being positioned within said recess, a plurality of sheet metal contactors located within said recess and movable with respect thereto into and out of bridging engagement with said pairs of contact tips, the main body portions of said contacts and said contactors comprising a base metal, such as brass, and the cooperative engaging surfaces thereof comprising inlaid portions of silver or an alloy thereof, springs interposed between the lower surfaces of the respective contactors and said base to bias said contactors into engagement with said contact tips, a molded insulating plunger slidable within said recess and adapted to rest upon said contactors jointly, a lever pivotally supported above said base and cooperable with the upper end portion of said plunger, said lever being adapted upon movement thereof in one direction to effect downward movement of said plunger and said contactors against the action of said springs, and said lever being adapted upon movement thereof in the opposite direction to permit upward movement of said contactors and said plunger under the action of said springs.

11. In a slow-break switch for control of alternating current circuits, in combination, a molded insulating base having a recess therein opening to the upper surface thereof, a plurality of pairs of punched sheet metal contact members secured to said base adjacent to the upper surface thereof, the tips of said contact members being positioned within said recess, a plurality of punched sheet metal contactors located within said recess and movable with respect thereto into and out of bridging engagement with said pairs of contact tips, the main body portions of said contacts and said contactors comprising a base metal, such as brass, and the cooperative engaging surfaces thereof comprising inlaid portions consisting of a noble metal, such as silver, or a suitable alloy embodying the same, coiled compression springs interposed between the lower surfaces of the respective contactors and said base to bias said contactors into engagement with said contact tips, a molded insulating plunger slidable within said recess and adapted to rest upon said contactors jointly, a lever pivotally supported above said base and cooperable with the upper end portion of said plunger, said lever being adapted upon movement thereof in one direction to effect downward movement of said plunger and said contactors against the action of said springs, said lever being adapted upon movement thereof in the opposite direction to permit upward movement of said contactors and said plunger under the action of said springs, and means comprising a plurality of spring pressed balls associated with said insulating base and a plurality of projections carried by said lever to insure movement of the latter to one or the other of its extreme positions upon release thereof.

12. In a slow-break switch for control of alternating current circuits, in combination, a molded insulating base having a recess formed therein and opening to the upper surface thereof, said recess including a plurality of pairs of vertical pockets, the pockets of said pairs being spaced longitudinally of said base, said base having a plurality of ledges formed therein and located in a common plane, a corresponding number of flat metal contacts of like form seated upon the respective ledges and having the tips thereof overlying the respective vertical pockets, a plurality of metal contactors the opposite ends of which respectively underlie said pairs of conv tact tips, said contactors being individually spring biased upwardly into engagement with said pairs of contact tips, means for rigidly securing said said recess and slidably engaging the walls thereof, said plunger having portions thereof seated upon the respectivebridging contactors intermediate the ends of the latter for support thereby, said plunger and said contactors having cooperating shoulders formed thereon to prevent displacement of the latter relatively to the former longitudinally of said base, and means including said plunger and the walls of said recess to pre- 'vent displacement of said contactors relatively to said plunger in a direction laterally of said base.

13. In a switch of the character described, in combination, a molded insulating plunger, having a main body portion and a plurality of fiat surfaces formed thereon and extending laterally from said main body portion in a common plane, a plurality of punched sheet metal contactors the intermediate portions of which are respectively adapted to seat flatwise against said flat surfaces, said plunger having a cam element at the upper end thereof, spring means for'effecting movement-of said plunger in one direction, and manually operable means cooperating with said cam element for effecting movement of said plunger in the opposite direction, said fiat surfaces acting upon-one direction of movement of said plunger to effect corresponding movement of said contactors. I

14. In a switch of the character described, in combination, a molded insulating plunger having a plurality of flat surfaces formed on the under side thereof and located in a common plane, sai'd plunger having a plurality of integral downward extensions of substantially rectangular form in transverse cross section, said downward extensions having vertical grooves formed therein and leading to the aforementioned flat surfaces respectively, a plurality of punched sheet metal contactors of substantially rectangular form the intermediate portions of which are respectively adapted to seat against said flat surfaces, each of said contactors being formed to cooperate with the side walls of said vertical grooves to insure against substantial longitudinal displacement of said contactors relatively to said plunger, one of said contactors being positioned between two of said downward extensions whereby substantial lateral displacment thereof is prevented, and a molded insulating base having a recess in which said plunger is slidable, the other contactors being'respectively positioned between one of said downward extensions and a wall of said recess whereby substantial lateral displacement of said last mentioned contactors is prevented.

15. Ina switch of the character described, in

combination, a molded insulating plunger having a plurality of fiat surfaces formed on the under side thereof and located in a common plane, said plunger having a plurality of integral downward extensions of substantially rectangular form in transverse cross section, said downward extensions having vertical grooves formed therein and leading to the aforementioned flat surfaces respectively, a plurality of punched sheet metal contactors of substantially rectangular form the intermediate portions of which are respectively adapted to seat against said flat surfaces, each of said contactors being formed to cooperate with the side walls of said vertical grooves to insure against substantial longitudinal displacement of said contactors relatively to said plunger, one of said contactors being positioned between two of said downward extensions whereby substantial lateral displacement thereof is prevented, a molded insulating base having a recess in which said plunger is slidable, the other contactors being respectively positioned between one of said downward extensions and a wall of said recess whereby substantial lateral displacement of said last mentioned contactors is prevented, a plurality of pairs of stationary contacts carried by said base and located in a common plane, spring means interposed between the bottom wall of said recess and the respective contactors to bias the latter upwardly into engagement with said pairs of contacts, and cam means cooperating with said plunger to effect disengagement of said contactors from said pairs of contacts and to releasably retain the same in disengaged position against the bias of said spring means.

16. As an article of manufacture, a molded insulating plunger for electric switches, of the slow-make, slowbreak type, said plunger having a main portion of substantially rectangular form to provide a plurality of fiat bottom surface portions located in a common plane, said plunger having a pair of integral portions of substantially rectangular form in transverse cross section extending downwardly from said main portion at points between said bottom surface portions, each of said integral portions having a pair of vertical grooves formed therein and leading respectively to two of said bottom surface portions for interlocking engagement with contactors of suitable form, said plunger having a recess formed in the upper end portion thereof and opening upwardly and laterally with respect thereto, and a circular metal member of substantial thickness rotatably seated edgewise within said recess.

17. In an electric switch of the character described, in combination, a molded insulating base having a recess formed therein and opening to the upper surface thereof, a plurality of pairs of contacts having the tips thereof located within said recess and having wiring terminal portions exposed upon the outer surface of said base, a molded insulating plunger slidable within said recess and guided by the walls of the latter, said plunger having a plurality of downwardly facing fiat surfaces formed thereon with integral barriers formed therebetween, a corresponding number of punched sheet metal contactors loosely associated with the respective flat surfaces for movement by said plunger to their lower extreme to rest upon said contactors jointly,

position, spring means individual to each of said contactors to respectively bias the latter toward their upper extreme position, a lever pivotally supported above said base, the lower end of said lever and said plunger having cooperating parts adapted to effect and permit movement of said plunger and said contactors to the lower and upper extreme positions thereof respectively upon movement of said lever to its opposite extreme positions selectively, and said plunger acting to releasably restrain said plunger in each of the extreme positions of the latter.

18. In an electric switch, in combination, a molded insulating base having a recess formed therein and opening to the upper surface thereof, a plurality of pairs of metal contact members secured to said base in a common plane spaced upwardly from the bottom wall of said recess, a plurality of metal contactors located within said recess and movable with respect thereto into and out of bridging engagement with the tips of the respective pairs of contact members, the main body portions of said contacts and said contactors comprising a base metal, such as brass, and the cooperative engaging portions thereof comprising silver, coiled compression springs interposed between the lower surfaces of the respective con-tactors and the bottom wall of said recess to bias said contactors into engagement with said contact tips, a molded insulating plunger slidable within said recess and adapted to rest upon said contactors jointly, a lever having a pivotal support above said base and having a cam surface cooperable with the upper end portion of said plunger, said lever being adapted upon movement thereof in one direction to effect downward movement of said plunger and said contactors against the action of said springs, and said lever being adapted upon movement thereof in the opposite direction to permit upward movement of said contactors and said plunger under the action of said springs.

19. In an electric switch, in combination, a molded insulating base having a. recess formed therein and opening to the upper surface thereof, a plurality of pairs of metal contact members secured to said base. in a common plane spaced upwardly from the bottom wall of said recess, a plurality of metal contactors located within said recess and movable with respect thereto into and out of bridging engagement with the tips of the respective pairs of contact members, coiled compression springs interposed between the lower surfaces of the respective contactors and the bottom wall of said recess to bias said contactors into engagement with said contact tips, a molded insulating plunger slidable within said recess and adapted a lever having a pivotal support above said base and having a cam surface cooperable with the upper end portion of said plunger, said lever being adapted upon movement thereof in opposite directions to respectively effect and permit downward and upward movements of said contactors and said plunger jointly, and spring biased means associated with said lever to insure movement of the latter to one or the other of its extreme positions upon release thereof.

\ ALVIN W. KRIEGER. 

